Artificially rendering images using viewpoint interpolation and extrapolation

ABSTRACT

Various embodiments of the present invention relate generally to mechanisms and processes relating to artificially rendering images using viewpoint interpolation and extrapolation. According to particular embodiments, a method includes applying a transform to estimate a path outside the trajectory between a first frame and a second frame, where the first frame includes a first image captured from a first location and the second frame includes a second image captured from a second location. The process also includes generating an artificially rendered image corresponding to a third location positioned on the path. The artificially rendered image is generated by interpolating a transformation from the first location to the third location and from the third location to the second location, gathering image information from the first frame and the second frame by transferring first image information from the first frame to the third frame and second image information from the second frame to the third frame, and combining the first image information and the second image information.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/800,640, filed on Jul. 15, 2015, entitled, “ARTIFICIALLYRENDERING IMAGES USING VIEWPOINT INTERPOLATION AND EXTRAPOLATION,” whichis incorporated by reference herein in its entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates to artificially rendering images usingviewpoint interpolation and/or extrapolation.

DESCRIPTION OF RELATED ART

With modern computing platforms and technologies shifting towards mobileand wearable devices that include camera sensors as native acquisitioninput streams, the desire to record and preserve moments digitally in adifferent form than more traditional two-dimensional (2D) flat imagesand videos has become more apparent. Traditional digital media formatstypically limit their viewers to a passive experience. For instance, a2D flat image can be viewed from one angle and is limited to zooming inand out. Accordingly, traditional digital media formats, such as 2D flatimages, do not easily lend themselves to reproducing memories and eventswith high fidelity.

Producing combined images, such as a panorama, or a three-dimensional(3D) image or model requires combining data from multiple images and canrequire interpolation or extrapolation of data. Most previously existingmethods of interpolation or extrapolation require a significant amountof data in addition to the available image data. For those approaches,the additional data needs to describe the scene structure in a denseway, such as provided by a dense depth map (where for every pixel adepth value is stored) or an optical flow map (which stores for everypixel the motion vector between the available images). This limits theefficiency of these methods in processing speed as well as transferrates when sending it over a network. Accordingly, improved mechanismsfor interpolation and extrapolation are desirable.

OVERVIEW

Provided are various mechanisms and processes relating to artificiallyrendering images using viewpoint interpolation and extrapolation.

In one aspect, which may include at least a portion of the subjectmatter of any of the preceding and/or following examples and aspects, amethod includes applying a transform to estimate a path outside thetrajectory between a first frame and a second frame, where the firstframe includes a first image captured from a first location and thesecond frame includes a second image captured from a second location.The process also includes generating an artificially rendered imagecorresponding to a third location positioned on the path. Theartificially rendered image is generated by interpolating atransformation from the first location to the third location and fromthe third location to the second location, gathering image informationfrom the first frame and the second frame by transferring first imageinformation from the first frame to the third frame and second imageinformation from the second frame to the third frame, and combining thefirst image information and the second image information.

In another aspect, which may include at least a portion of the subjectmatter of any of the preceding and/or following examples and aspects, acomputer readable medium includes code for applying a transform toestimate a path outside the trajectory between a first frame and asecond frame, where the first frame includes a first image captured froma first location and the second frame includes a second image capturedfrom a second location. The computer readable medium also includes codefor generating an artificially rendered image corresponding to a thirdlocation positioned on the path. The artificially rendered image isgenerated by interpolating a transformation from the first location tothe third location and from the third location to the second location,gathering image information from the first frame and the second frame bytransferring first image information from the first frame to the thirdframe and second image information from the second frame to the thirdframe, and combining the first image information and the second imageinformation.

These and other embodiments are described further below with referenceto the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may best be understood by reference to the followingdescription taken in conjunction with the accompanying drawings, whichillustrate particular embodiments of the present invention.

FIG. 1 illustrates an example of a configuration where an artificiallyrendered image is generated for a chosen viewpoint on a trajectorybetween two frames.

FIG. 2 illustrates an example of combining image information gatheredfrom two frames to artificially render an image for another frame usingweighted image information.

FIG. 3 illustrates an example of a process for generating anartificially rendered image from two frames.

FIG. 4 illustrates an example of combining image information gatheredfrom two frames to artificially render an image in another frame usingmultiple layers extracted from surround views.

FIGS. 5A-5B illustrate an example of an image transformation between twoframes using tracked control points between the two frames.

FIG. 6 illustrates an example of viewpoint extrapolation outside of thetrajectory between two frames using multiple layers and the parallaxeffect.

FIG. 7 illustrates an example of a process for extrapolating a viewpointoutside the trajectory between two frames.

FIG. 8 illustrates an example of a process for interpolating a layerusing a panoramic representation.

FIG. 9 illustrates an example of a process for generating anartificially rendered image from a surround view.

FIG. 10 illustrates a particular example of a computer system that canbe used with various embodiments of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to some specific examples of theinvention including the best modes contemplated by the inventors forcarrying out the invention. Examples of these specific embodiments areillustrated in the accompanying drawings. While the present disclosureis described in conjunction with these specific embodiments, it will beunderstood that it is not intended to limit the invention to thedescribed embodiments. On the contrary, it is intended to coveralternatives, modifications, and equivalents as may be included withinthe spirit and scope of the invention as defined by the appended claims.

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention.Particular embodiments of the present invention may be implementedwithout some or all of these specific details. In other instances, wellknown process operations have not been described in detail in order notto unnecessarily obscure the present invention.

Various systems and methods for analyzing the spatial relationshipbetween multiple images and video together with location informationdata, for the purpose of creating a single representation, a surroundview, which eliminates redundancy in the data, and presents a user withan interactive and immersive active viewing experience, is described inU.S. patent application Ser. No. 14/530,669 by Holzer et al., filed onOct. 31, 2014, titled “Analysis and Manipulation of Images and Video forGeneration of Surround Views,” which is incorporated by reference hereinin its entirety and for all purposes. According to various embodimentsdescribed therein, a surround view provides a user with the ability tocontrol the viewpoint of the visual information displayed on a screen.

According to various embodiments, a surround view is a multi-viewinteractive digital media representation. The data used to generate asurround view can come from a variety of sources. In particular, datasuch as, but not limited to, two-dimensional (2D) images can be used togenerate a surround view. These 2D images can include color image datastreams such as multiple image sequences, video data, etc., or multipleimages in any of various formats for images, depending on theapplication. Another source of data that can be used to generate asurround view includes location information. This location informationcan be obtained from sources such as accelerometers, gyroscopes,magnetometers, GPS, WiFi, IMU-like systems (Inertial Measurement Unitsystems), and the like. Yet another source of data that can be used togenerate a surround view can include depth images. These depth imagescan include depth, 3D, or disparity image data streams, and the like,and can be captured by devices such as, but not limited to, stereocameras, time-of-flight cameras, three-dimensional cameras, and thelike.

In the present example embodiment, the data can then be fused together.In some embodiments, a surround view can be generated by a combinationof data that includes both 2D images and location information, withoutany depth images provided. In other embodiments, depth images andlocation information can be used together. Various combinations of imagedata can be used with location information, depending on the applicationand available data.

In the present example embodiment, the data that has been fused togetheris then used for content modeling and context modeling. According tovarious examples, the subject matter featured in the images can beseparated into content and context. The content can be delineated as theobject of interest and the context can be delineated as the scenerysurrounding the object of interest. According to various embodiments,the content can be a three-dimensional model, depicting an object ofinterest, although the content can be a two-dimensional image in someembodiments. Furthermore, in some embodiments, the context can be atwo-dimensional model depicting the scenery surrounding the object ofinterest. Although in many examples the context can providetwo-dimensional views of the scenery surrounding the object of interest,the context can also include three-dimensional aspects in someembodiments. For instance, the context can be depicted as a “flat” imagealong a cylindrical “canvas,” such that the “flat” image appears on thesurface of a cylinder. In addition, some examples may includethree-dimensional context models, such as when some objects areidentified in the surrounding scenery as three-dimensional objects. Invarious embodiments, the models provided by content modeling and contextmodeling can be generated by combining the image and locationinformation data.

According to various embodiments, context and content of a surround vieware determined based on a specified object of interest. In someexamples, an object of interest is automatically chosen based onprocessing of the image and location information data. For instance, ifa dominant object is detected in a series of images, this object can beselected as the content. In other examples, a user specified target canbe chosen. It should be noted, however, that a surround view can begenerated without a user specified target in some applications.

In the present example embodiment, one or more enhancement algorithmscan be applied. In particular example embodiments, various algorithmscan be employed during capture of surround view data, regardless of thetype of capture mode employed. These algorithms can be used to enhancethe user experience. For instance, automatic frame selection,stabilization, view interpolation, filters, and/or compression can beused during capture of surround view data. In some examples, theseenhancement algorithms can be applied to image data after acquisition ofthe data. In other examples, these enhancement algorithms can be appliedto image data during capture of surround view data.

According to various examples, view interpolation can be used to improvethe viewing experience. In particular, to avoid sudden “jumps” betweenstabilized frames, synthetic, intermediate views can be rendered on thefly. This can be informed by content-weighted keypoint tracks and IMUinformation, as well as by denser pixel-to-pixel matches. If depthinformation is available, fewer artifacts resulting from mismatchedpixels may occur, thereby simplifying the process. As described above,view interpolation can be applied during capture of a surround view insome embodiments. In other embodiments, view interpolation can beapplied during surround view generation.

In the present embodiment, a surround view is generated after anyenhancement algorithms are applied. The surround view can provide amulti-view interactive digital media representation. In variousexamples, the surround view can include a three-dimensional model of thecontent and a two-dimensional model of the context. However, in someexamples, the context can represent a “flat” view of the scenery orbackground as projected along a surface, such as a cylindrical orother-shaped surface, such that the context is not purelytwo-dimensional. In yet other examples, the context can includethree-dimensional aspects.

According to various embodiments, surround views provide numerousadvantages over traditional two-dimensional images or videos. Some ofthese advantages include: the ability to cope with moving scenery, amoving acquisition device, or both; the ability to model parts of thescene in three-dimensions; the ability to remove unnecessary, redundantinformation and reduce the memory footprint of the output dataset; theability to distinguish between content and context; the ability to usethe distinction between content and context for improvements in theuser-experience; the ability to use the distinction between content andcontext for improvements in memory footprint (an example would be highquality compression of content and low quality compression of context);the ability to associate special feature descriptors with surround viewsthat allow the surround views to be indexed with a high degree ofefficiency and accuracy; and the ability of the user to interact andchange the viewpoint of the surround view. In particular exampleembodiments, the characteristics described above can be incorporatednatively in the surround view representation, and provide the capabilityfor use in various applications. For instance, surround views can beused to enhance various fields such as e-commerce, visual search, 3Dprinting, file sharing, user interaction, and entertainment.

As described above, view interpolation can be used to improve theviewing experience. In particular, to avoid sudden “jumps” betweenstabilized frames, synthetic, intermediate views can be rendered duringacquisition or generation of a surround view. However, according tovarious embodiments, only a limited amount of image frames are storedfor each surround view for storage efficiency. In some examples, theselection of these frames is based on the motion of the camera ratherthan on time. For instance, a new frame is sampled only if the cameramoved sufficiently with respect to the previously sampled frame.Consequently, in order to provide a smooth viewing experience for a userinteracting with a surround view, artificially rendered frames must begenerated. These artificially rendered frames serve to close the gapbetween two sampled frames that would otherwise appear to have a “jump”between them. Accordingly, by generating these artificially renderedframes, smooth navigation within the surround view becomes possible.

Various embodiments described below include methods of viewpointinterpolation and extrapolation that can be used to generateartificially rendered frames. In various examples, interpolation betweenframes is performed along a path between the frames. In some instances,this path can follow a non-linear trajectory. In addition, variousdescribed extrapolation methods allow the artificially rendered frame torepresent a view from a location that is not on the trajectory of therecording camera or in between two sampled frames. By providinginterpolation and extrapolation methods for paths between or beyond theoriginally provided frames, various artificially rendered views can beprovided for a surround view.

With reference to FIG. 1 , shown is an example of a configuration wherean artificially rendered image is generated for a viewpoint at LocationX on a trajectory between Location A and Location B. In this example, asingle transform for viewpoint interpolation is used along thetrajectory between two frames, Frame A 102 and Frame B 104. As shown,Frame A 102 represents an image captured of objects 108 and 110 by acamera 112 located at Location A 122. Frame B 104 represents an imagecaptured of object 108 by a camera 114 located at Location B 124. In thepresent example, the transformation (T_AB) is estimated between the twoframes, where T_AB maps a pixel from frame A to frame B. Thistransformation is performed using methods such as homography, affine,similarity, translation, rotation, or scale.

In the present example, an artificially rendered image at Location X126, which can also be denoted as a viewpoint position at x \in [0, 1]on the trajectory between frame A and B, where frame A is located at 0and frame B at 1, is then generated by interpolating the transformation,gathering image information from Frames A and B, and combining the imageinformation. In the present example, the transformation is interpolated(T_AX and T_XB). One way to interpolate this transformation is toparameterize the transformation T_AB and linearly interpolate thoseparameters. However, this interpolation is not limited to linearinterpolations and other methods can be used within the scope of thisdisclosure. Next, image information is gathered from both Frames A and Bby transferring image information from Frame A 102 to Frame X 106 basedon T_AX and by transferring image information from Frame B 104 to FrameX 106 based on T_XB. Finally, the image information gathered from bothFrames A and B is combined to generate an artificially rendered image atLocation X 126.

In the present example, combining the image information gathered fromboth Frames A and B can be done in various ways. With reference to FIG.2 , shown is one example of a way to combine image information gatheredfrom both Frames A and B to artificially render an image in Frame Xusing weighted image information. As shown, image information is takenfrom Frame A 202 and Frame B 204 to generate an image in Frame X 206.Image information in Region 208 of Frame X 206 is taken from Frame A.Image information in Region 210 of Frame X 206 is taken from Frame B.Image information in Region 210 of Frame X 206 includes information fromboth Frame A 202 and Frame B 204. In order to account for the overlap ininformation, the image information is weighted. Specifically, theinformation is combined using the image information from Frame A 202using 1−x and the image information from Frame B 204 using x.

With reference to FIG. 3 , shown is an example of a process forgenerating an artificially rendered image from two frames 300. In thisexample, a transformation is estimated between a first frame and asecond frame at 302. The transformation is estimated using methods suchas homography, affine, similarity, translation, rotation, or scale. Asdescribed above with regard to FIG. 1 , the first frame includes a firstimage captured from a first location (Location A 122) and the secondframe includes a second image captured from a second location (LocationB 124). In some examples, the first image and second image areassociated with the same layer. Next, an artificially rendered image isrendered corresponding to a third location. This third location ispositioned on a trajectory between the first location and the secondlocation, as shown as Location X 126 in FIG. 1 .

The artificially rendered image is generated in a number of steps.First, a transformation is interpolated from the first location to thethird location and from the third location to the second location at304. In some instances, interpolating the transformation includesparameterizing the transformation from the first location to the thirdlocation and from the third location to the second location.Furthermore, in some examples, the parameterized transformation is thenlinearly interpolated.

Next, image information is gathered from the first frame and the secondframe at 306 by transferring first image information from the firstframe to the third frame based on the interpolated transformation andsecond image information from the second frame to the third frame basedon the interpolated transformation. Finally, the first image informationand the second image information is combined to yield the artificiallyrendered image. In some examples, combining the first image informationand the second image information includes weighting the first imageinformation from the first frame and the second image information fromthe second frame.

According to various embodiments, the process can end with combining thefirst image information and second image information at 308. However,according to the present example, the process shown continues withdetermining whether an occlusion is present in the artificially renderedimage at 310. Such an occlusion is created by a change in layerplacement between the first frame and second frame. Specifically, thefirst image and second image may include foregrounds and backgroundsthat include one or more layers, each layer corresponding to a region ofimage pixels that share a similar motion, as described in more detailbelow with regard to FIG. 4 . These layers can move relative to eachother. In some cases, the layers may move in a manner causing anocclusion in a combined image. If an occlusion is detected, then themissing data is replaced to fill the first occlusion at 310. In someinstances, the missing data is obtained by interpolation orextrapolation. In other instances, the missing data is obtained from thefirst frame or the second frame. In yet other instances, the missingdata is obtained from another frame (separate from the first and secondframe) that includes image information corresponding to the missingdata. In another example, the missing data is obtained by extrapolatingfrom surrounding image data. This surrounding image data includesinformation from frames located near the first location and secondlocation.

With reference to FIG. 4 , shown is an example of combining imageinformation gathered from both Frames A and B to artificially render animage in Frame X by using multiple layers of an image. The presentexample uses the method described above with regard to FIG. 3 , wherethe first frame and second frame are made up of two or more layers. Inparticular, the first frame, which includes a view at Time A 302,includes a background layer 306 and foreground layer 304. The secondframe, which includes a view at Time B 308, includes a background layer312 and foreground layer 310. In some examples, foreground and/orbackground can include one or more layer. In the present example, alayer is a region of image pixels that share a similar motion, based onfactors such as depth and or speed of the corresponding real worldobject.

In the present example, viewpoint-interpolation can be used to generatean artificially rendered image as described above with regard to FIG. 3. In addition, because different motions of the layers can createocclusions and/or regions with missing data, the process can alsoinclude methods for filling the regions corresponding to any detectedocclusions. Whether data is occluded or missing is based on the orderingof layers. Although the layers are expected to stay in the same order,they can switch order if the objects change their depth location withinthe scene. For instance, occlusions are created if a first layer movesin front of a second layer, where the first layer is closer to thecamera than second layer. In the case that the first layer isnon-see-through, image information from the first layer is takenwherever the first and second layer overlap. In the case that the firstlayer is partially see-through, image information is taken from bothlayers according to the opacity of the first layer. This process canalso be extended to more than two layers.

As described above with regard to FIG. 3 , missing information can beobtained in various ways, including interpolation or extrapolation. Forinstance, missing data can be taken from only one of the frames,depending on which frame includes a view of the missing data. In anotherexample, the missing data can be taken from other frames where thisregion is visible. For instance, in a surround view that includesvarious frames and viewpoints, other frames can be used to fill in thismissing data. In another example, the missing data can be extrapolatedfrom surrounding image data, to create artificial image data thatestimates what the missing data would look like. In yet another example,viewpoint-extrapolation using multiple layers can be applied outside ofthe trajectory between the two frames, by moving the different layers inperpendicular motion to the trajectory motion, as shown in more detailwith regard to FIG. 6 . According to various examples, the transformbetween the two frames can be an image transformation or a 3Dtransformation. An image transformation can use methods such ashomography, affine, similarity, translation, rotation, scale. For a 3Dtransformation, layers are moved with respect to their depth and the 3Dtransformation, according to various embodiments.

With reference to FIGS. 5A-5B, shown is an example of an imagetransformation between two frames using tracked control points betweenthe two frames. In particular, FIG. 5A shows a first frame of a scene ata first time T1 and FIG. 5B shows a second frame of the scene at asecond time T2. A set of control points 502, 504, 506, 508, 510, and 512are tracked between the two frames, such that their locations are knownin both frames. An intermediate frame X at x \in [0, 1] between thesetwo frames can be generated by interpolating the location of all controlpoints individually for x and then computing the image data for frame Xby interpolating all pixel locations using those control points. In someexamples, the set of control points are located within a single layerthat includes particular objects viewable in the first frame and secondframe. In this case, generating an artificially rendered image mayinclude interpolating image data for multiple layers and combining theselayers. In other example, each pixel in the first frame corresponds to acontrol point in the set of control points. Accordingly, each pixel istracked and interpolated in that instance.

In the present embodiment, an artificially rendered image is generatedas intermediate frame X by tracking a set of control points between thefirst frame and the second frame, and interpolating individual controlpoints for the third location X using the set of control points andinterpolating pixel locations using the individual control points. Asshown, the first frame includes a first image captured from a firstlocation and the second frame includes a second image captured from asecond location. In one example, interpolating the pixel locationsincludes interpolation using barycentric coordinates based on three ormore control points. In another example, interpolating the pixellocations includes interpolation using splines. In yet another example,interpolating the pixel locations includes interpolation using finiteelements. In yet another example, interpolating the pixel locationsincludes using motion of the nearest control point. In some examples,interpolating pixel locations using the individual control pointsincludes using dense optical flow. In other examples, interpolatingpixel locations using the individual control points includes using depthdata.

With reference to FIG. 6 , shown is an example of viewpointextrapolation outside of the trajectory between two frames usingmultiple layers and the parallax effect. Using multiple layers,viewpoint-extrapolation outside of a trajectory between two frames canbe achieved by moving the different layers in perpendicular motion tothe trajectory motion. As shown, a scene 408 includes multiple layersLayer A 402, Layer B 404, and Layer C 406. Although not shown, twoframes capturing images of the scene 408 can be obtained by moving acamera along camera motion 416. Comparing the two images will showparallax motion in the direction 412. As shown in the figure, the amountof parallax motion 410 of each of the layers can indicate movement ordifferences between the frames. Although not indicated in the figure,the different layers 402, 404, and 406 can each have different amountsof parallax motion.

In the present embodiment an artificially rendered image is generatedusing this parallax effect. In particular, a set of control points (notshown) is moved perpendicular to a trajectory between a first frame anda second frame. In this example, the first frame includes a first imagecaptured from a first location and the second frame includes a secondimage captured from a second location and each control point is movedbased on an associated depth of the control point. Specifically, controlpoints located at a further depth are moved less than control points ata closer depth in some examples. Additionally, in some applications,each pixel in the first image corresponds to a control point in the setof control points. Furthermore, in addition to having a concrete depthassociated with a point, it is also possible to infer the depth from theamount of frame-to-frame motion of the control points.

Next, an artificially rendered image corresponding to a third locationoutside of the trajectory is generated by extrapolating individualcontrol points using the set of control points for the third locationand extrapolating pixel locations using the individual control points.In some examples, extrapolating the pixel locations includesextrapolation using barycentric coordinates based on three or morecontrol points. In other examples, extrapolating the pixel locationsincludes extrapolation using splines. In yet other examples,extrapolating the pixel locations includes extrapolation using finiteelements. In other instances, extrapolating the pixel locations includesusing motion of a nearest control point. In yet other instances,extrapolating pixel locations using the individual control pointsincludes using dense optical flow.

With reference to FIG. 7 , shown is an example of a process forextrapolating a viewpoint outside the trajectory between two frames.This process can be viewed as an extension to the process described withregard to FIG. 3 , where viewpoints for locations outside of thetrajectory between Frame A and Frame B are extrapolated by applying atransform which warps the image according the curvature and direction ofthe estimated path.

In the present embodiment, a transform is applied to estimate a pathoutside the trajectory between a first frame and a second frame at 702.The first frame includes a first image captured from a first locationand the second frame includes a second image captured from a secondlocation. In some examples, the first image and second image areassociated with the same layer. Furthermore, this process can be appliedto various layers and the resulting images representing the layers canbe combined to generate a complete image. Next, an artificially renderedimage corresponding to a third location positioned on the path isgenerated. The artificially rendered image is generated by firstinterpolating a transformation from the first location to the thirdlocation and from the third location to the second location at 704.Image information is then gathered from the first frame and the secondframe at 706 by transferring first image information from the firstframe to the third frame based on the interpolated transformation andsecond image information from the second frame to the third frame basedon the interpolated transformation. Finally, the first image informationand the second image information is combined at 708.

According to present embodiment, the transform can implement variousfeatures. For instance, the transform can implement features such ashomography, spherical projection, and/or cylindrical projection. Thesefeatures can be used alone or in conjunction with one another inapplying the transform. Additional features not mentioned can also beimplemented within the scope of this disclosure.

The present embodiment describes one method of extrapolating a viewpointoutside the trajectory between two frames. However, additional methodsfor extrapolating such viewpoints can also be implemented in otherembodiments. For instance, as described above with regard to FIG. 6 ,another way to extrapolate viewpoints for locations outside of thetrajectory between two frames can include moving the layers and/orcontrol points perpendicular to the trajectory direction based on theirdepth. Specifically, layers/control points at greater depth are movedless than layers/control points at lesser depth. Depending on thecharacteristics of the frames, different methods can be chosen toprovide an appropriate result.

With reference to FIG. 8 , shown is an example of a process forinterpolating a layer using a panoramic representation. In this example,the span of a layer is not restricted to two frames but is constructedfrom multiple frames. Specifically, a panorama is created from thecorresponding background regions and combined into a panoramicrepresentation. This panorama representation is then used to interpolatethe corresponding layer. Although this process is described in terms ofa background layer, this process can also be extended to other types oflayers. For instance, the process can be applied to layers that includeobjects, such as context layers.

In the present embodiment, a set of control points is tracked betweenmultiple frames associated with the same layer at 802. In some examples,each pixel corresponds to a control point in the set of control points.In these cases, each pixel is then interpolated based on the set ofcontrol points for the artificially rendered image. Next, a panoramicrepresentation is generated from the multiple frames at 804. Individualcontrol points are then interpolated from the set of control points at806 for a desired frame or layer. Pixel locations are then interpolatedfor this frame or layer using the individual control points at 808. Fromthis interpolation, the artificially rendered image/layer is generated.

According to various embodiments, interpolation can be implemented usinga variety of methods. For instance, interpolating the pixel locationscan include interpolation using barycentric coordinates based on threeor more control points. In some examples, interpolating the pixellocations includes interpolation using splines. In other examples,interpolating the pixel locations includes interpolation using finiteelements. In yet other examples, interpolating the pixel locationsincludes using motion of a nearest control point. In addition,interpolating pixel locations using the individual control pointsincludes using dense optical flow in some applications. Althoughparticular examples of interpolation methods are described, anycombination of these or other methods can be used.

With reference to FIG. 9 , shown is an example of a process forgenerating an artificially rendered image from a surround view. Asdescribed previously, a surround view is a multi-view interactivedigital media representation. In some examples, the surround view isgenerated from multiple images having location information, and at leasta portion of overlapping subject matter. Furthermore, according tovarious embodiments, the surround view is generated by interpolatingbetween the multiple images and/or extrapolating data from the multipleimages. In the present example, a surround view can be decomposed intoone or more background panoramic representations and, in some examples,one or more foreground 3D models. An image at a specific viewpoint isthen rendered by projecting the 3D model(s) and the panoramicrepresentation(s) into a frame according to the current viewpoint andthe depth and orientation of the 3D model(s).

In the present embodiment, a content model is obtained from a surroundview at 902. This content model is a foreground three-dimensional modelincluding at least one object. In some examples, obtaining the contentmodel from the surround view includes extracting the content model fromthe surround view. At 904, a context model is obtained from the surroundview. This context model is a background panoramic representationincluding scenery surrounding any objects in the content model. In someexamples, obtaining the context model from the surround view includesextracting the context model from the surround view. Next, the contentmodel is projected into a frame corresponding to a desired viewpoint at906. The context model is also projected into the frame corresponding tothe desired viewpoint at 908. According to various embodiments, thecontent model and context model are projected according to the depth andorientation of the content model. The artificially rendered image at thedesired viewpoint is generated from a combination of the projectedcontent and context at at 910.

Various examples of viewpoint interpolation and extrapolation aredescribed in the present disclosure. According to various embodiments,one or a combination of methods can be used to generate a singleartificially rendered image. For instance, one layer can be handledusing the method described with regard to FIG. 3 , another layer can behandled using the method described with regard to FIGS. 5A-5B, and abackground layer can be handled using the method described with regardto FIG. 8 . Any combination of methods can be used within the scope ofthis disclosure. Additionally, any one method can be used alone togenerate an artificially rendered image.

The methods presented in this disclosure are highly efficient and can berun on a mobile platform in real-time. The various methods require onlyvery small amounts of additional data and are therefore extremelywell-suited for data that needs to be sent over a wireless network (e.g.LTE). In addition, the methods are sufficiently regularized to handleproblematic cases without creating jarring artifacts. Accordingly, themethods described herein are suitable for generating artificiallyrendered images on mobile devices, etc.

Various computing devices can implement the methods described. Forinstance, a mobile device, computer system, etc. can be used to generateartificially rendered images. With reference to FIG. 10 , shown is aparticular example of a computer system that can be used to implementparticular examples of the present invention. For instance, the computersystem 1000 can be used to provide generate artificially rendered imagesaccording to various embodiments described above. In addition, thecomputer system 1000 shown can represent a computing system on a mobiledevice. According to particular example embodiments, a system 1000suitable for implementing particular embodiments of the presentinvention includes a processor 1001, a memory 1003, an interface 1011,and a bus 1015 (e.g., a PCI bus). The interface 1011 may includeseparate input and output interfaces, or may be a unified interfacesupporting both operations. When acting under the control of appropriatesoftware or firmware, the processor 1001 is responsible for such taskssuch as optimization. Various specially configured devices can also beused in place of a processor 1001 or in addition to processor 1001. Thecomplete implementation can also be done in custom hardware. Theinterface 1011 is typically configured to send and receive data packetsor data segments over a network. Particular examples of interfaces thedevice supports include Ethernet interfaces, frame relay interfaces,cable interfaces, DSL interfaces, token ring interfaces, and the like.

In addition, various very high-speed interfaces may be provided such asfast Ethernet interfaces, Gigabit Ethernet interfaces, ATM interfaces,HSSI interfaces, POS interfaces, FDDI interfaces and the like.Generally, these interfaces may include ports appropriate forcommunication with the appropriate media. In some cases, they may alsoinclude an independent processor and, in some instances, volatile RAM.The independent processors may control such communications intensivetasks as packet switching, media control and management.

According to particular example embodiments, the system 1000 uses memory1003 to store data and program instructions and maintain a local sidecache. The program instructions may control the operation of anoperating system and/or one or more applications, for example. Thememory or memories may also be configured to store received metadata andbatch requested metadata.

Because such information and program instructions may be employed toimplement the systems/methods described herein, the present inventionrelates to tangible, machine readable media that include programinstructions, state information, etc. for performing various operationsdescribed herein. Examples of machine-readable media include hard disks,floppy disks, magnetic tape, optical media such as CD-ROM disks andDVDs; magneto-optical media such as optical disks, and hardware devicesthat are specially configured to store and perform program instructions,such as read-only memory devices (ROM) and programmable read-only memorydevices (PROMs). Examples of program instructions include both machinecode, such as produced by a compiler, and files containing higher levelcode that may be executed by the computer using an interpreter.

Although many of the components and processes are described above in thesingular for convenience, it will be appreciated by one of skill in theart that multiple components and repeated processes can also be used topractice the techniques of the present disclosure.

While the present disclosure has been particularly shown and describedwith reference to specific embodiments thereof, it will be understood bythose skilled in the art that changes in the form and details of thedisclosed embodiments may be made without departing from the spirit orscope of the invention. It is therefore intended that the invention beinterpreted to include all variations and equivalents that fall withinthe true spirit and scope of the present invention.

What is claimed is:
 1. A method comprising: obtaining a content modelfrom a surround view, wherein the surround view is a multi-viewinteractive digital media representation and the content model is aforeground three-dimensional model including at least one object,wherein the content model comprises one or more layers; obtaining acontext model from the surround view, wherein the context model is abackground panoramic representation including scenery surrounding the atleast one object, wherein the context model comprises one or morelayers; and generating an artificially rendered image corresponding to afirst viewpoint by projecting the content model into a first framecorresponding to the first viewpoint and projecting the panoramicrepresentation into the first frame, wherein the artificially renderedimage is generated by moving different layers in different motions,wherein generating the artificially rendered image includes generatingusing viewpoint-interpolation and any missing information is filled inusing viewpoint-extrapolation, wherein viewpoint-extrapolation isachieved by moving different layers in a motion perpendicular to thetrajectory from the first frame to a second frame.
 2. The method ofclaim 1, wherein obtaining the content model from the surround viewincludes extracting the content model from the surround view.
 3. Themethod of claim 1, wherein obtaining the context model from the surroundview includes extracting the context model from the surround view. 4.The method of claim 1, wherein the content model and context model areprojected according to the depth and orientation of the content model.5. The method of claim 1, wherein the surround view is generated from aplurality of images having location information, wherein the pluralityof images include at least a portion of overlapping subject matter. 6.The method of claim 5, wherein the surround view is generated byinterpolating data between the plurality of images.
 7. The method ofclaim 5, wherein the surround view is generated by extrapolating datafrom the plurality of images.
 8. A system comprising: a processor; andmemory, the memory storing instructions to execute a method, the methodcomprising: obtaining a content model from a surround view, wherein thesurround view is a multi-view interactive digital media representationand the content model is a foreground three-dimensional model includingat least one object, wherein the content model comprises one or morelayers; obtaining a context model from the surround view, wherein thecontext model is a background panoramic representation including scenerysurrounding the at least one object, wherein the context model comprisesone or more layers; and generating an artificially rendered imagecorresponding to a first viewpoint by projecting the content model intoa first frame corresponding to the first viewpoint and projecting thepanoramic representation into the first frame, wherein the artificiallyrendered image is generated by moving different layers in differentmotions, wherein generating the artificially rendered image includesgenerating using viewpoint-interpolation and any missing information isfilled in using viewpoint-extrapolation, wherein viewpoint-extrapolationis achieved by moving different layers in a motion perpendicular to thetrajectory from the first frame to a second frame.
 9. The system ofclaim 8, wherein obtaining the content model from the surround viewincludes extracting the content model from the surround view.
 10. Thesystem of claim 8, wherein obtaining the context model from the surroundview includes extracting the context model from the surround view. 11.The system of claim 8, wherein the content model and context model areprojected according to the depth and orientation of the content model.12. The system of claim 8, wherein the surround view is generated from aplurality of images having location information, wherein the pluralityof images include at least a portion of overlapping subject matter. 13.The system of claim 12, wherein the surround view is generated byinterpolating data between the plurality of images.
 14. The system ofclaim 12, wherein the surround view is generated by extrapolating datafrom the plurality of images.
 15. A non-transitory computer readablemedium storing instructions to execute a method, the method comprising:obtaining a content model from a surround view, wherein the surroundview is a multi-view interactive digital media representation and thecontent model is a foreground three-dimensional model including at leastone object, wherein the content model comprises one or more layers;obtaining a context model from the surround view, wherein the contextmodel is a background panoramic representation including scenerysurrounding the at least one object, wherein the context model comprisesone or more layers; and generating an artificially rendered imagecorresponding to a first viewpoint by projecting the content model intoa first frame corresponding to the first viewpoint and projecting thepanoramic representation into the first frame, wherein the artificiallyrendered image is generated by moving different layers in differentmotions, wherein generating the artificially rendered image includesgenerating using viewpoint-interpolation and any missing information isfilled in using viewpoint-extrapolation, wherein viewpoint-extrapolationis achieved by moving different layers in a motion perpendicular to thetrajectory from the first frame to a second frame.
 16. Thenon-transitory computer readable medium of claim 15, wherein obtainingthe content model from the surround view includes extracting the contentmodel from the surround view.
 17. The non-transitory computer readablemedium of claim 15, wherein obtaining the context model from thesurround view includes extracting the context model from the surroundview.
 18. The non-transitory computer readable medium of claim 15,wherein the content model and context model are projected according tothe depth and orientation of the content model.
 19. The non-transitorycomputer readable medium of claim 15, wherein the surround view isgenerated from a plurality of images having location information,wherein the plurality of images include at least a portion ofoverlapping subject matter.
 20. The non-transitory computer readablemedium of claim 15, wherein the surround view is generated byinterpolating data between a plurality of images.